Hey man! I'm 6'5 240lbs and I ride all kinds of bikes man! Doing tricks/stunts on bikes is all about skill and finesse. For example, a 150lbs kid might snap his cranks doing a sketchy dirtjump where I might not break anything while jumping down a 10 stair. It's all about how you finesse your bike. People turn their noses up at those oldschool plastic mag wheels because they 'crack' but I have an '87 General Hustler Pro that has the stock 20+ year old Skyway Tuff wheels on it and I haven't had ANY problems with the rim 'cracking'. The key is learning the limits/strengths and weaknesses of your bike.
if you are planning on purchasing a complete BMX bike, I guarantee you will have problems with cranks stripping/bending and wheels denting and tires blowing, but that's just what happens when you enter the BMX world with extra baggage lol. As you progress, you'll most likely start to mod your bikes with stronger parts. You're gonna fall inlove with the sport and that love will force you to self-teach yourself about BMX componentry, so you will learn what parts are strong enough to handle your riding. The key to NOT blowing out tires is to get heavy duty/extra thick innertubes and OVER-PRESSURING them! people will tell you this is stupid but I pump up my tires until they're ROCK solid! It's the only way I'll get any life out of them. If you DONT do this, you will CONSTANTLY get pinch-flats when you 'case' curbs and ledges (happened to me HUNDREDS of times before I figured out how to avoid it).
So anyway, the answer is yes, a BMX bike CAN handle big riders. The challenge is really whether the rider can handle the bike. And since you are a tall rider, you may want to look for a large frame size. The largest BMX size is a 22" toptube only offered on the Macneil Deuce Deuce frame. If you don't want this frame than anything larger than a 21" frame should be ok. (you can always get longer stems and higher handlebars and stuff if needed) So best of luck to you man! I hope you fall as inlove with the sport as I have! if you feel these BMX bikes are too small, you may want to consider BMX "cruisers" (BMX bikes with 24" wheels) or Urban/DJ style mountain bikes! I ride all of these style bikes and they're ALL great! I know you're attracted to BMX but check out this MTB website. Just make an account and check out the photos and stuff... its pretty damn gnarly!
www.pinkbike.com
BTW, cracking a frame doesn't mean your a 'good' rider lol. It's just a natural occurance that happens in the sport. maybe not as often as flat tires or bent rims but it does happen
